1// SPDX-License-Identifier: GPL-2.0
  2/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */
  3#include <linux/memremap.h>
  4#include <linux/module.h>
  5#include <linux/pfn_t.h>
  6#include "../nvdimm/pfn.h"
  7#include "../nvdimm/nd.h"
  8#include "bus.h"
  9
 10static struct dev_dax *__dax_pmem_probe(struct device *dev)
 11{
 12	struct range range;
 13	int rc, id, region_id;
 14	resource_size_t offset;
 15	struct nd_pfn_sb *pfn_sb;
 16	struct dev_dax_data data;
 17	struct nd_namespace_io *nsio;
 18	struct dax_region *dax_region;
 19	struct dev_pagemap pgmap = { };
 20	struct nd_namespace_common *ndns;
 21	struct nd_dax *nd_dax = to_nd_dax(dev);
 22	struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
 23	struct nd_region *nd_region = to_nd_region(dev->parent);
 24
 25	ndns = nvdimm_namespace_common_probe(dev);
 26	if (IS_ERR(ndns))
 27		return ERR_CAST(ndns);
 28
 29	/* parse the 'pfn' info block via ->rw_bytes */
 30	rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
 31	if (rc)
 32		return ERR_PTR(rc);
 33	rc = nvdimm_setup_pfn(nd_pfn, &pgmap);
 34	if (rc)
 35		return ERR_PTR(rc);
 36	devm_namespace_disable(dev, ndns);
 37
 38	/* reserve the metadata area, device-dax will reserve the data */
 39	pfn_sb = nd_pfn->pfn_sb;
 40	offset = le64_to_cpu(pfn_sb->dataoff);
 41	nsio = to_nd_namespace_io(&ndns->dev);
 42	if (!devm_request_mem_region(dev, nsio->res.start, offset,
 43				dev_name(&ndns->dev))) {
 44		dev_warn(dev, "could not reserve metadata\n");
 45		return ERR_PTR(-EBUSY);
 46	}
 47
 48	rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", &region_id, &id);
 49	if (rc != 2)
 50		return ERR_PTR(-EINVAL);
 51
 52	/* adjust the dax_region range to the start of data */
 53	range = pgmap.range;
 54	range.start += offset;
 55	dax_region = alloc_dax_region(dev, region_id, &range,
 56			nd_region->target_node, le32_to_cpu(pfn_sb->align),
 57			IORESOURCE_DAX_STATIC);
 58	if (!dax_region)
 59		return ERR_PTR(-ENOMEM);
 60
 61	data = (struct dev_dax_data) {
 62		.dax_region = dax_region,
 63		.id = id,
 64		.pgmap = &pgmap,
 65		.size = range_len(&range),
 66		.memmap_on_memory = false,
 67	};
 68
 69	return devm_create_dev_dax(&data);
 70}
 71
 72static int dax_pmem_probe(struct device *dev)
 73{
 74	return PTR_ERR_OR_ZERO(__dax_pmem_probe(dev));
 75}
 76
 77static struct nd_device_driver dax_pmem_driver = {
 78	.probe = dax_pmem_probe,
 79	.drv = {
 80		.name = "dax_pmem",
 81	},
 82	.type = ND_DRIVER_DAX_PMEM,
 83};
 84
 85static int __init dax_pmem_init(void)
 86{
 87	return nd_driver_register(&dax_pmem_driver);
 88}
 89module_init(dax_pmem_init);
 90
 91static void __exit dax_pmem_exit(void)
 92{
 93	driver_unregister(&dax_pmem_driver.drv);
 94}
 95module_exit(dax_pmem_exit);
 96
 97MODULE_DESCRIPTION("PMEM DAX: direct access to persistent memory");
 98MODULE_LICENSE("GPL v2");
 99MODULE_AUTHOR("Intel Corporation");
100MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM);